Electric heater for street cars and the like



April 27 1926.

W. G. HARTWIG smc'rruc HEATER FOR STREET cans AND was LIKE Filed April 26,

1924 2 Sheets-Sheet 1 April 27 1926.

W. G. HARTWIG ELECTRIC HEATER FOR STREET CARS AND THE LIKE Filed April .26, 1924 2 Sheets-Sheet 2 T. Li;

Patented Apr. 27, 12 26.

F A I hi I WILLIAM G. I-IARTWIG, 03E CHICAGO, ILLINOIS, ASSIGNOR TO RAILWAY UTILITY COMPANY, OF CHICAGO, ILLINOIS, A. CORPORATION OF ILLINOIS.

ELECTRIC HEATER- FOR STREET CARS AND THE LIKE.

Application filed April 26, 1924. Serial No. 709,085.

To all whom it may concern:

Be it known that I, WILLIAM G. Hanrwre, a citizen of the United States, residing at Chicago, in the countyof Cook and State of Illinois, have invented certain new and useful Improvements in Electric Heaters for Street Cars and the like, of which the following is a specification.

My invention relates more particularly to electric heaters to be attached to the truss planks ofpassenger cars, i. e. along the sides of a car a short distance above the fioor. The object of the invention is to providea housing and mounting for electric heating elements, adaptable to the above mentioned location and support which is sightly, durable under the conditions to which it is subjected in such location, efficient in utilizing the heat developed by the element and safe both with respect to the support on which it is mounted and the heating elements itself. My improved housing and support comprises a casing perforated for the passage of air and a bafile plate on which the heating element is mounted and which is so arranged as to provide for the passage of a current of air between the same and the truss plank on which the casing is mounted, the heating element being mounted on the baffle, as a consequence of which'arrangement that portion of the heat given off by the heating element'which is transmitted to its support is taken up by the current of air and supplied to the interior of the car 1nstead of being transmitted to the outside of the car as in similar constructions of the prior art. I

In the drawings, accompanying and forming a part of the specification, Figure 1 1s a perspective view of a truss plank heater embodying my invention; Fig. 2 a transverse section on the plane of the line 2-2 of Fig. 1; Fig. 3 a vertical longitudinal section through the housing showing the heating element and its connections in elevation, the construction being shown as broken away in order to condense the figure; Fig. 4. is a hori-' zontal section partly in elevation, on an en larged scale of a detail showing an end of the heater; Fig. 5 is a vertical section on an enlarged scale onthe plane of the line 5-5 of Fig. 1; Fig. 6 is a perspective, partly broken away, of a somewhat different form of the invention; Fig. T a front elevation of one end of the same; and Fig. 8 a transverse vertical section on the line 8-8 of Fig. 7 Each part is identified by the same reference character wherever it occurs in the several views.

In the drawings I have shown my invention in connection with a known form of electric heating element found upon the market, but it is to be understood that this form of heater per se is not of my invention and the invention may be used with other forms of heating elements. The form of heater shown comprises a sheath or cas ing 6 of sheet metal enclosing a resistor wire or ribbon imbedded in insulating material, the ends of the wire or ribbon being attached to terminal posts 7, one of which is shown in Fig. 4. The heating element is supported independently of the terminals by lugs or brackets 8 attached respectively to insulating blocks 9 at the opposite .ends of the housing. As best seen in Figs. 4 and 5, the metal sheath 6 is collapsed at its ends beyond the resistor strip and filling and perforated at 10 for the passage of the insulating sleeve 11 by which said sheath is insulated from the screw bolt 12 by means of which it is mounted upon the bracket 8 above mentioned. The insulation of the bolt from the sheath is completed by insulating washer 13 and a metal washer 14 is placed between the head of the screw and the insulating washer. The insulating sleeve 11 is formed with a broad flange, and intermediate said flange and the bracket 8, the screw bolt passes through a hole in the end of a connector 15 by means of which the bracket is electrically connected to the terminal of the heating element. A nut 16 and nut lock 17 complete the structure by which the heating element is mounted on the bracket 8. .As best shown in Fig. 3, each bracket 8 is mounted on its insulating support by screws 18, one of which may serve for the lead wire which is connected thereby to the corresponding end of the heater. IVhile the heating element just described is satisfactory for the purpose, it forms no part of the present invention except as a part of the general combination, as as before mentioned other forms of heater elements may be substituted therefor.

The form of the invention shown in'Figs. 1 to 5 inclusive is adapted to be secured to the truss plank and project outwardly into the The bot om wall 19, from; wall 520 and top wall 21 of the casing are n'efcrably formed from a single sheet of metal suitably bent at the corners 22-23 thereof and likewise bent at 2 l25 to form flanges 26, 27 by which said casing may be attached to the truss plank. The bottom a id front walls are perforated at 28, 29 for the passage of air currents. The ends 30 of the housing are preferably formed of struck-up sheet metal and spot welded or otherwise secured to the main body thereof.

The above mentioned ball'le 31 is L-shaped in cross section and of approximately the length of the housing and is mounted therein so that its vertical leaf 32 is spaced away from the truss plank on which the heater is mounted and the horizontal leaf 32-3 thereof is spaced away from and parallel to the top of the casing. The bottom of the cas- :ing is formed with a series of holes 34- ad jacent the flange on the edge thereof, and the top of the front wall of the casing is formed with a horizontal series of holes 35 so that a free passage is afforded for air from the holes in the bottom wall upwardly 'ehind the vertical leaf of the balile and then forwardly over the horizontal leaf of the baffle to the openings 35. Thus, the heat absorbed by the baillc 31 from the electric heater is absorbed by the air currents pass ing back of and above the same so that said heat is utilized in heating the car and not transmitted to the truss plank where it would be wasted and further might overheat and perhaps injure the plank. The baffle is supported at its ends by brackets 40 struck up out of sheet metal and secured to the battle by the screws 41 by which the respective insulating blocks 9 are secured to said baffle. As shown in Fig. 5, the screws are received in sockets 42 cast. in the insulating blocks. The brackets are secured to the truss plank by screws 43 independently of the housing and are turned up at their outer ends as at 44 to lie against the end walls of the housing. One of the end walls and the adjacent bracket are perforated as at 45 to serve as an outlet for the wires loading to the respective ends of the heating element.

The form of the invention illustrated in Figs. 6 to 8 inclusive is designed to seat within an opening cut in the truss plank with the face thereof substantially flush with the outer face of the plank. The casing comprises a top wall 50, a bottom wall 51, a rear wall 52, and end walls 53, the top, bottom and end walls being flanged as at 54 so that when the heater is seated in the opening in the truss plank the flanges 54 may be screwed to the adjacent edges of the opening. The face plate 5'5 is perforated as shown and secured at its edges over the flanges of the body portion of the casing.

The bottom wall 51 of the'casing is perforated along its rear edge as at 56 but otherwise the walls of said casing iiupcrlorate.

In the specific illustration of the invention in the drawings Figs. 6 to 8, two clef:- tric heatingelcments 57 are used, being mounted at their respective ends on common insulating blocks 58 by means of bra cts 59, 60. Preferably the upper lunch 5 59 are bcnt'outwadly so that the heating elements are in different verticil planes, there by increasing the heating effect. The insulating blocks above referred to are inounted on a guide or baffle plate 61 which is cured by screws 62 to the barn of the boss ing. The baffle 61 is spaced from the rea' wall'of the housing by sleeves and the upper end of the baffle is bent forwardly as at 64, the, upper edge thereof resting in contact with the perforated front plate. Preferably the lower end of the battle is bent slightly forward as at 65. There is thus provided a free passage for air entering through the holes 56 in the bottom wall of the casing up behind and a .t-ove the baffle plate tothe outlet openings 68 at the top edge of the front plate whereby the heat radiated or otherwise transmitted to the baflle is taken up and carried into the body of the car.

I claim:

1. An electric heater of the class described comprising a casing having a perforated front wall adapted to be secured to a vertical support, means within the casing for supporting an electric heater and a batiie plate mounted within the casing and between the heating element and the casing support and spaced from the latter, there being perforations in the lower part of the casing permitting the flow of air currents upward behind the bafiie.

2. In a heater of the class described, a casing having a perforated front wall adapted to be attached to a vertical support, a heating element mounted within the casing and a battle arranged to the rear of the heating element and spaced from the back of the casing and projecting forwardly above the heating element to permit currents 'of air to circulate back of and above the heating elen'ient.

In an electric heater of the cla-ss described, a casing having a perforated front wall adapted to be attached to a vertical wall, a vertical bafile mounted in the casing and spaced from the back thereof and an electric heating element mounted on the baffle, there being openings in the lower and upper part of the casing communicating with the space back of the battle to permit upward circulation of air therethrough.

4. In an electric heater of the class described a casing having a perforated front wall adapted to be attached to a vertical wall or support, a baffle L-shaped-in cross section, and means for spacing the hallle from and mounting casing there being openings in the lower and upper parts ot' the casing to permit the circulation of air hack of the baflle.

In an electric heater of the class described, a casing perforated as to its bottom and trout Walls and in'ipertorate as to its top Wall, an L-shaped battle mounted in the asing with one leat thereof vertical and the other end horizontal and spaced from the top of the casing to provide an air passage along the hack and top of the casing communicating at its ends with the perforait upon the rear of the tions in the front and bottom Walls and an electric heater mounted on the battle.

6. An electric heater of the class described a casing having an impertorate top Wall and perforated front and bottom Walls, an L-shaped haflle arranged in the casing with one leaf thereot parallel to and spaced from the oottom of the top Wall and the other lea't parallel to and spaced from the rear wall, an electric heater mounted on the battle and brackets supporting the battle independently ot the casing.

WILLIAM G. HARTWIG. 

